The identification of differentially downregulated genes in hypoxia or G9a overexpression.
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: You Mie Lee
PROVIDER: E-GEOD-64710 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:To identify differentially downregulated genes in hypoxia or G9a overexpression, we have employed whole genome microarray expression profiling.
2015-01-07 | GSE64710 | GEO
Project description:Epigenetic mechanisms play important roles in the regulation of tumorigenesis, and hypoxia-induced epigenetic changes may be key drivers of the adaptation of cancer cells to the hypoxic microenvironment typical of solid tumors. Previously, we showed that loss-of-function or inhibition of the oncogenic H3K9 methyltransferase G9A attenuates tumor growth and constitutes an important strategy for cancer management. However, the mechanisms by which blockade of G9A leads to a tumor suppressive effect remain poorly understood. Here, we show that G9A is highly expressed in breast cancer compared to normal breast tissue and is associated with poor prognosis in patients, where it may function as a potent oncogenic driver in this cancer type. In agreement with this, G9A inhibition leads to increased cell death, impaired cell migration, reduced cell cycle and downregulated anchorage-independent growth. Interestingly, whole transcriptome analysis revealed that a number of previously non-responsive genes become amenable to hypoxia following G9A inhibition, including many targets that drive cancer cell survival. This was accompanied by the upregulation of the hypoxia inducible factors HIF1A and HIF2A during the use of G9A inhibition to curb cancer cell growth even under normoxic conditions. Therefore, we show that G9A is a key mediator of oncogenic processes in breast cancer cells and cancer therapeutics involving G9A inhibition can be used successfully to attenuate oncogenicity. However, cancer cells mount a survival response via activation of the HIF pathway that may necessitate the additional suppression of HIF signaling for improved efficacy in the eradication of the disease.
2017-12-20 | GSE89891 | GEO
Project description:Posttranslational modifications of histone N-terminal tails influence the status of chromatin and eventually control the transcriptional outcome of a particular gene. As a histone H3K9 methyltransferase (HMTase) in higher eukaryotes, G9a-mediated transcriptional repression is the major epigenetic silencing machinery. UHRF1 (ubiquitin-like with PHD and ring finger domains I) binds to hemi-methylated DNA and plays essential role in maintenance of DNA methylation by recruiting DNMT1. Here, we provide evidence that UHRF1 is transcriptionally downregulated by H3K9 HMTase G9a. We found that increased expression of G9a along with transcription factor YY1 specifically represses UHRF1 transcription. We uncovered showed that G9a regulates UHRF1-mediated H3K23 ubiquitylation and proper DNA replication maintenance by FACS analysis and propose that H3K9 HMTase G9a is a specific epigenetic regulator of UHRF1.
2018-12-31 | GSE63149 | GEO
Project description:G9a is able to silence gene expression in hypoxic condition by increasing histone H3K9me2. We have identified a set of genes that are negatively regulated by G9a in hypoxia-dependent manner. In this dataset, we include the expression data obtained from MCF7 breast epithelial cells that have been transfected with control (WT) or G9a shRNAs (KD) and exposed to either normoxia or hypoxia. These data are used to obtain 829 genes that are differentially expressed in response to hypoxia, and 205 genes that are sentisive to G9a level. 4 samples were analysed. We generated comparisons between WT and KD in normoxic as well as hypoxic condition. Genes differentially expressed in hypoxic condition were selected followed by selection of genes that lose this differential expression upon G9a knockdown.
2015-12-31 | E-GEOD-59449 | biostudies-arrayexpress
Project description:G9a (EHMT2) and the G9a-like protein GLP (EHMT1) form a stable G9a/GLP heterodimer in embryonic stem cells and function cooperatively to establish and maintain the abundant repressive H3K9me2 modification, in addition to modifying several non-histone proteins. The G9a-dependent H3K9me2 is implicated in lineage-specific gene silencing and covers large chromosomal domains. While the mechanism of H3K9me2maintenance by G9a/GLP is known, how new patterns of this modification are established is not well understood. With this in mind, we used FLAG affinity purification of G9a under two different stringency conditions (150 and 300 mM NaCl) coupled with mass spectrometry to identify proteins stably associated with G9a/GLP, which could serve as potential recruiters of the complex to unmodified chromatin.
2016-03-16 | PXD003466 | Pride
Project description:Gene expression in eukaryotes is tightly linked to the methylation state of specific lysine residues within the N-terminal region of the core histone proteins. While the mechanisms connecting histone lysine methylation to effector protein recruitment and control of gene activity are increasingly well understood, it remains unknown whether non-histone chromatin proteins are targets for similar modification-recognition systems. Here we show that histone H3 and the H3 methyltransferase G9a share a conserved methylation motif that is both necessary and sufficient to mediate in vivo interaction with the potent epigenetic regulator Heterochromatin Protein 1 (HP1). As with H3, G9a-HP1 interaction is dependent on lysine methylation and can be reversed by adjacent phosphorylation. NMR analysis demonstrates that the HP1 chromodomain recognizes methyl-G9a through a binding mode similar to that used in recognition of methyl-H3, and that adjacent phosphorylation directly antagonizes G9a-HP1 interaction. In addition to uncovering the chromodomain as a generalized methyl-lysine binding module, these data identify histone-like modification cassettes (or âhistone mimicsâ) as an entirely new class of non-histone methylation targets, and directly demonstrate the relevance of the principles underlying the histone code to the regulation of non-histone proteins. Experiment Overall Design: Two independent Affymetrix gene expression microarray analyses were performed on samples from G9a-deleted MEFs reconstituted with empty vector (delta), wild type FLAG-G9a (WT), FLAG-G9a K165A (K165A) or FLAG-G9a H1093K catalytic mutant (H1093K).
2008-06-15 | E-GEOD-8011 | biostudies-arrayexpress
Project description:The identification of differentially downregulated genes in hypoxia or G9a overexpression
| PRJNA271698 | ENA
Project description:Target genes regulated by G9a in bladder cancer cells T24 In this dataset, we include the expression data obtained from bladder cancer cells T24 treated with G9a siRNA or negative control siRNA. These data are used to obtain genes that are differentially expressed in response to G9a konckdown.
2019-05-29 | GSE115341 | GEO
Project description:Cocaine-mediated repression of the histone methyltransferase (HMT) G9a has recently been implicated in transcriptional, morphological, and behavioral responses to chronic cocaine administration. Here, using a ribosomal affinity purification approach, we find that G9a repression by cocaine occurs in both Drd1 (striatonigral)- and Drd2 (striatopallidal)-expressing medium spiny neurons (MSNs). Conditional knockout and overexpression of G9a within these distinct cell types, however, reveals divergent behavioral phenotypes in response to repeated cocaine treatment. Our studies further indicate that such developmental deletion of G9a selectively in Drd2 neurons results in the unsilencing of transcriptional programs normally specific to striatonigral neurons, and the acquisition of Drd1-associated projection and electrophysiological properties. This partial striatopallidal to striatonigral ‘switching’ phenotype in mice indicates a novel role for G9a in contributing to neuronal subtype identity, and suggests a critical function for cell-type specific histone methylation patterns in the regulation of behavioral responses to environmental stimuli. Polyribosome associated mRNAs from 2-5 month old, age and sex matched Drd1-Cre; Drd1-TRAP; G9afl/fl and Drd1-TRAP; G9afl/fl, Drd2-Cre; Drd2-TRAP; G9afl/fl and Drd2-TRAP; G9afl/fl mice (n = 2-4 mice/genotype/drug treatment, 2 hours after the last of eight repeated cocaine injections of 20 mg/kg/day) were obtained as previously described. EGFP labeled ribosomes and associated mRNAs were immunoprecipitated using a mix of two monoclonal anti-GFP antibodies (50 μg of clones #19C8 and #19F7 for each IP, available at Sloan-Kettering Monoclonal Antibody Facility). Purified mRNA was amplified and processed for microarray and qPCR analysis using the Affymetrix two-cycle cDNA Synthesis kit (Affymetrix) as previously described. Affymetrix Mouse Genome 430 2.0 arrays were used in all experiments. Information regarding the array design and features can be found at www.affymetrix.com. Mouse Genome 430 2.0 arrays were scanned using the GeneChip Scanner 3000 (Affymetrix) and globally scaled to 150 using the Affymetrix GeneChip Operating Software (GCOS v1.4).
2014-02-05 | E-GEOD-54656 | biostudies-arrayexpress
Project description:modENCODE_submission_5611 This submission comes from a modENCODE project of Gary Karpen. For full list of modENCODE projects, see http://www.genome.gov/26524648 Project Goal: We aim to determine the locations of the major histone modifications across the Drosophila melanogaster genome. The modifications under study are involved in basic chromosomal functions such as DNA replication, gene expression, gene silencing, and inheritance. We will perform Chromatin ImmunoPrecipitation (ChIP) using genomic tiling arrays. We will initially assay localizations using chromatin from three cell lines and two embryonic stages, and will then extend the analysis of a subset of proteins to four additional animal tissues/stages. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf EXPERIMENT TYPE: CHIP-chip. BIOLOGICAL SOURCE: Strain: G9a mutant (official name : G9a mutant genotype : G9a[RG5]/G9a[RG5] outcross : 3 transgene : n/a tags : homologous recombination tag : none description : Mutation generated by end-out homologous recombination at the G9a locus. The entire open reading frame of G9a has been removed. Developmental Stage: 3rd Instar Larvae; Genotype: G9a[RG5]/G9a[RG5]; Transgene: n/a; NUMBER OF REPLICATES: 4; EXPERIMENTAL FACTORS: Strain G9a mutant (official name : G9a mutant genotype : G9a[RG5]/G9a[RG5] outcross : 3 transgene : n/a tags : homologous recombination tag : none description : Mutation generated by end-out homologous recombination at the G9a locus. The entire open reading frame of G9a has been removed. Antibody H3K9me3 abcam (target is H3K9me3); Developmental Stage 3rd Instar Larvae
2013-03-13 | E-GEOD-45102 | biostudies-arrayexpress